Thanks to Stephen Carlson for pointing this out to me:
Matthew C. Baldwin, Whose Acts of Peter? Text and Historical Context of the Actus Vercellenses (PhD dissertation, University of Chicago, 2002)
Full text of this successful PhD Dissertation is available in PDF. Would that more people would do this, not least because it would save me or our library from forking out to UMI to purchase theses! Seriously, it is a great way of getting your work known, especially since recent PhDs are inevitably at the beginning of their careers. I'd think there'd be no doubt at all that you can get your work much more widely read by doing this. You have to be very keen to read something before you purchase from UMI.